Control system



G. A. WAI DIE CONTROL SYSTEM Filed Nov. 12, 1942 Nov. 28, 1944.

INVENTOR GEORGEAWALDI E, BY

. 3 bx 7 IT ull!!! lllllllJlllP-qllllllllllllll lllll l I I ATTORNEYS said reciprocable I I Patented Nov. 28, 1-944,

Ge'o'rgc A; Waldle, Edison, Ohio, asslgnor to The Hydraulic Development 0011)., Inc., Wilmlng'' ton, DeL, a corporation of Delaware Application November 12,1942, Serial No. 465,519 8 Claims. (01. 6097) I This invention relates to control systems, and,

movable members, the movements of which have to be coordinated with each other.

It is an object of this invention to provide a "control system including two, members movable relative to each other in a predetermined coordinated manner, in which the coordinated movement of the said members iscontrolled hydraulically.

It is another object to provide a. hydraulic con- ,trol system including a reciprocable member adapted to be controlled in its movement by two fluid operableelements movable simultaneously in two different directions, in which supply of actuating fluid pressure to said elements is con.- trolled by the movement of one of saidelements.

It is still another object to provide a hydraulic" 4 control system including tworeciprocable members and power storage means, in whichthe power storage means is charged in response -to the travel of one Of the said reciprocalble members and is adapted, at a predetermined point. of travel in particular, to control systems, including two l by accumulator means charged in response to the movement of said first hydraulic motor.

- Structural arrangement Referring to the drawing indetail, the system shown therein comprises a hack saw, generally designated I, and composed of a saw blade 2 fastened to the frame 3', which latter is provided with a. ledge-shaped portion, not ShQWn in the drawing, and slidably mounted in a slot 4 of a link 5 for guiding the frame 3.

The link 5 is pivotally connected by means of the pivot 6 to a stationarily mounted earl, while -gthe other end of-the link 5 is pivotally connected to a' piston rod 8 through a link 8a.. The piston rod 8,has connected thereto a double-acting piston 9 reciprocaablymounted in a cylinder Ill. One

end of the cylinder 1 llv communicates with a con- 1 duit comprising a check valve [2 and leading of said one reoiprocable memberj to release stored energy to the other reciprocable member for actuating the same. 1 4

A still further object of this invention consists in the provision of a hydraulic control sys tern including two fluid operable plungers adapted to be moved in one direction by pressure fluid from one and'the same fluid source-whereas one of the said 'plungers is movable in the opposite direction by energy stored in response to the movement ofthe'other plunger during move- 'ment thereof in said one direction.

These and other objects and advantages of the invention will appear more clearly from the following-specification in connection with the accompanying. drawing which illustrates the m vention by way'of example in connection with a hack saw.

General arrangement The hydraulic system according to the inventlon comprises a reciprocable element reciprocable by a first hydraulic motor, while a second hydraulic motor is provided for imposing upon member an additional movement. I

While the firsthydraulic motor is-actuated for movement in both directions by a pressure 'fluid source, the second hydraulic motor is actuated to a conduit I3. The conduit I3 leads to amanually controlledfour-way valve l4 and also com- I municates with a conduit l5, which latter has one end connected to the conduit H and includesa pressure regulating valve 16. The pressure regulating valve J6 may be of any conventional clersign and is' so constructed that it maintains a predetermined. pressure at its outlet, in this instance, at its left' side, irrespective of pressure variations at its inlet, in the drawing at its right side. .i

The other end of the conduit is connected with a cylinder I I having reciprocably mounted therein a double-acting piston l8, which latteris connected through piston rod l9 and a link 20 with one end of the' saw frame 3. The piston rod I9 has adjustably mounted thereon an arm. 2i which for movement in one direction by the said fi uid source, while its movement in the opposite'dir'e'ction is brought about by pressure fluid delivered nected to an adjusting screw 29.

in it turn is connected with a control rod 22. The control rod 22 has adjustably mounted thereon two control members 23 and 24 and has furthermore connected thereto an abutment member 25, which latter is connected to or abuts one end of a spring 26,.the other end of which is in engagement with one side of a plunger 21. The other side of the plunger 21 engages one end ofa spring 28, the opposite end of which is con- The springs 26 and 28 may be of the samestrength and structure. However, if desired, the spring 28 may be lighter than the spring 26, since the spring 28 serves only to return the plunger 21 sucking in oil, whereas the spring 26 serves as the energy, source of an accumulator. This-accumulator is made up of the plunger2'l and a cylinder 30 which houses the plunger 21 and springs 26 and 28, and i closed at one end adjacent the adjusting screw 29. A conduit 3| leads from this end to a conduit 32 and comprises a'check valve, 33. The conduit 32 has one end connected to the manually controlled four-way valve l4, while the other end is connected to a fluid reservoir or tank 34. Connected to the tank 34 is a conduit 35 leading to thesuction side of a pump 36, the pressure side of which is connected to the conduit 31 leading to the valve l4.

Branching off from the conduit 31 is a conduit 38 leading to a rotary four-way valve, generally designated 39. The valve 39 includes a casing 40 connected with the conduits 4!, 42 and 43 and also comprises a. valve rotor 44 with passageways 45 and 46 therein for controlling fluid connection between the conduits 38, 4|, 42 and 43. The conduit 43 is connected to one end of the cylinder ll. Branching off from the conduit 42 is a conduit 41 leading to'a rotary valve, generally designated 48, comprising a casing 49, which latter is connected with the conduits 50 and The conduit 50 communicates with a conduit 52, which latter comprises a choke valve 53 and communicates with one end of the cylinder 10. The choke valve 53 is adapted to be by-passed by a conduit 54 including a check valve 55. The conduit 5i comprises a check valve 56 and communicates with the conduit 3|.

Rotatably mounted in the valve casing 49 is a valve rotor 51 with passageways 58, 59 and 66 for controlling fluid connection between the conduits 41, 50 and 5|. The valve rotors 44 and 51 are rigidly connected to one and the same shaft, as diagrammatically indicated by line 6!, to which shaft is also rigidly connected a control disc 62. The control disc 62 is provided with two notches 63 and 64 adapted alternately to be engaged by a.

circular shaped latch member 65 carried by a,

spring 66, one end of which is connected to a stationary point. The disc 62 has rigidly connected thereto two pins 67 and 66 for cooperation with a lever 69 which is slidable about the hub of the disc 62. Arranged between the lever 69 and one ear ll, connected to the disc-32, is a spring 12, while a spring 13, equivalent to the spring 12, is mounted between the lever 69 and an ear l4,

likewise connected to the disc 62.

Operation It may be assumed that all parts of the control system occupy the position shown in the drawing, and that it is now desired to perform a working blade 2 moves toward the left, while simultaneously moving toward the'work piece 15. The saw blade 2 is, therefore, pressed against the work piece while it is actually sawing.

The cutting pressure of the saw is controlled by the pressure regulating valve l6, while the feed of the saw blade 2 toward the work piece 15 is controlled by the choke valve 53, which latter controls the escape of fluid from the lower portion of the cylinder I0 while the piston 9 is moving downwardly.

While the piston l8 and saw blade 2 thusmove toward the left, the control rod 22, connected by the arm 2| to the piston rod l9, likewise moves toward the left. This movement causes the abutment member 25 to compress the spring 26, while the plunger 21 is held stationary, due to the fact that the fluid between the plunger 21 and the closed end of the casing 40 is trapped by the check valve 33 and the valve 43.

When, during the leftward movement of the control rod 22, the control member 24 engages the lever 69, the latter is carried along by the control member 24, and since the disc 62 is held stationary by the latch member 65, the lever 69 loads the spring 12. When the piston l8 and, thereforealso the blade 2 approach their de sired left hand end position, the lever 69 has been shifted in anticlockwise direction to such an extent that it engages the pin 68. Further leftward movement of the piston l8 and thereby also of the control rod 22, causes the control member 24 to shift the lever 69 further in anticlockwise direction which latter now, due to its engagement with the pin 68, shifts the disc 62 in anticlockwise direction. In this way the latch member '65, carried by the spring 66, is forced to yield, thereby ment of the disc 62 causes a corresponding movecycle of the device with automatic control thereof. To this end, the valve i4 is shifted into its effective position, in which fluid connection is interrupted between the conduits 32, 52, i3 and 3? pertaining to the valve l4. Thereupon the operatorstarts the driving motor, not shown, for the pump 36. As a result thereof, pressure fluid is delivered by the pump 36 through conduits 3'! and 38, passageway and conduit 4i into the conduit l5. From here a part of the fluid passes to the right hand end of the cylinder ll where it acts upon the piston It so as to cause the latter to move the hack saw I toward the left. Another part of the fluid is conveyed from the conduit 15 through the pressure regulating valve i6 and conduit- II to the upper portion of the cylinder 1 0 where the fluid acts upon the piston 9 so as to move the latter downwardly. -In this way, the link 5 is moved in anti-clockwise direction, while simultaneously the frame 3 is guided in the slot 4 of the link 5.

It will be clear that, as a result of the combined movements of the piston rods 49 and 3, the saw ment of the valve rotors 44 and 51. As a result thereof, the passageway 46 in the valve rotor 44 now interconnects the conduits 4| and 42, while the passageway 45 interconnects the conduits 38 and 43. Similarly, the valve rotor 51 has been shifted to such an extent that the conduit 58 now communicates with the conduit 5! while the passageway 59 now communicates with the conduit 50. In other words, the valve rotor 51 now interconnects the ,conduits 56 and 5|.

Due to the shifting movement of the valve rotor 44, pressure fluid from the pump 36 is now conveyed through the conduits 3'7 and 36, passageway 46 and the conduit 43 to the left hand the cylinder 30 through conduits 3| and 5 l. passageways 53 and 58, conduits ill, 52 and 54 into the lower portion of the cylinder ll, thereby lifting the piston '3- so that the piston rod 8 r moves the link 5 in clockwise direction by a corresponding angle. In this way, the blade -2 is moved'upwardly so that no more force is exerted by the blade 2 against the work piece 15. Since, as'mentioned before, the piston I8 is now moving toward the right, the'saw blade 2 moves toward the right without exerting piece pressure on the work When the piston I 8 has moved toward the right "a predetermined distance, corresponding to the position, of the control member 23, the latter engages the lever 69 and moves the same in clock-- wise direction during further rightward movement of the control rod 22 brought about by furinder portion intermediate the plunger 21 and the closed end of the cylinder 30, which suction efiect causes fluid from'the tank 34 to enter the cylinder 30 through conduit 32, check valve 33 and conduit-3|.

When'the piston l8 approaches the end. of its rightward movement, the lever 69engages the pin 6! and, during iurther rightward movement of the piston l8, and thereby, control member 23,

causes the disc 62 likewise to rotate in clockwise direction. 'As a result thereof, the latch member 65 is forced out of the notch 63 and the spring 13 instantaneously shifts the disc 62 in clockwise direction until the'latch member 65 again engages the notch 64. The shifting movement of" the disc 62 thus brought about, causes a simulta- When the valve is in the position shown in the drawing, no fluid connection is establishedbetween the conduits leading to thesaid valve.

While, according to the showing'dn'the drawing,the saw'performs a cuttingstroke whenever it is pushed outwardly, it is, of course, under-'- stood, that, if desired, the saw may perform a working stroke whenever it is drawn inwardly. To this end, it is merely necessary to reverse the connections of conduits cylinder l0.

It will also 'be appreciated that, while the invention has been described in connection with a hack saw,'it is, of course, understoodthat the invention is by no means limited thereto, and

may be applied in connection with other elements adapted to. perform movements which ther rightward movement of the piston I8. This have to be coordinated with each other.

It will be understood that I desire to comprehend within my invention such modifications as comewithin the scope of the claims.

Having thus fully described my invention, what I claim as new. and desire to secure by Letters Patent, is:

1. In a hydraulic control system, first fluid operable motor means, a fluid source for selectively supplying pressure fluid to said motor means for actuating the same, second fluid operable motor means, valve means for conveying pressure fluid from said fluid source to said first motor means, power storage means adapted to be charged in response to 'a movement of said first motormeans, and means associated ,with said first motor means and operable in response to a predetermined travel thereof for actuating said valve means to convey power from said power storage means to said second'motor means to actuate the same, While maintaining fluid connection between said first motor means and said neous shifting movement of the valve rotors 44 and 51 so that these valve rotors are again moved into the position shown in the drawing. Pressure fluid from the pump 36 ,is then again conveyed to the right hand end of the cylinder I1 andwill force the piston Hi to move toward the'left. The cycle is then repeated in the manner pre-- viously described. r

For purposes of loading and unloading the work piece, it is desirable to control the piston 9 manually. This may be effected by actuation of the valve l4 selectively into a.first position,

in which fluid connection is established between the conduit 31 and theconduit I3, while simultaneously the conduits 52 and 32 are interconnected. It will then be clear that pressurefluid delivered by the pump 36 will pass through con- I duits 31, I3 and H into the upper'portion of the cylinderlll, thereby moving the piston rod 8 and the hack saw ldownwardly so that the'latter properly engages, the work piece. I

When it is desired to unload the workpiece, the valve I4 is shifted into a second'position, in which fluid connection is established between the conduits 31 and .52, while the conduit I3 isbrought into communication with the conduit 32. Pressure fluid delivered by the pump. 36 will then pass through conduits 31, 52 and 54 into the lower portion of the cylinder ill and lift fluid source.

2. Ina control system, a first fluid operablemotor, a fluid source for supplying pressure fluid to said'motor to reciprocate the same, a second fluid operablemotor, means for establishing fluid connection between saidsecond motor and said fluidusource to cause movement of said second' motor in a first direction, power storage means adapted in response to the travel of said first motor to store power, and means adapted in response to a predetermined travel of said first motor. for interrupting fluid connection between said fluidsource and said second motor, While establis'hing fluid connection between the latter I and said power storage means to thereby cause 'movement of said second motor in asecond direction.

3.; In a control system, first fluid operable motor means, a fluid source for supplying pressure fluid to said motor means for reciprocating the same, second fluid operable motor means, valve means operable to simultaneously efiect fluid connection between said fluid source and said first motor means and also between said fiuid source and said second motor means for '65 moving said first and second motor means in a first direction, power storage means operable in response to the travel of said first motor means the piston 9 and thereby the hack saw I so that the latter will completely release the work piece 15 and allow removal thereof.

for storin power, and means responsive to a predetermined travel of said first motor means to cause said valve means to interrupt fluid connection between said second motor means and said fluid source, while establishing fluid connection between said power storage means and said second motor means, to thereby move the latter in a second direction while said first motor II and 54 with the means is reversed by fluid from said fluid source.

4. In a control system, a first reciprocable fluid operable member, a second reciprocable fluid operable member, said second member being remember to actuate the latter by said power storage means.

5. In a control system, a first fluid operable member, a second fluid operable member, power storage means adapted to be charged in response to the travel of said first member and also adapted to elease fluid pressure to said second fluid operable member, a fluid source, valve means movable into a first position for simultaneously conveying fluid pressure from said fluid source to said first and second fluid operable members and movable into a second position for conveying fluid pressure from said fluid source to said first fluid operable member while simultaneously preventing said fluid source from conveying fluid pressure to said second fluid operable member and causing said storage means to release fluid pressure to said second fluid operable member, and means responsive to a predetcrmined position of said first fluid operable member for shifting said valve mean from said first position into said second position.

6. In a control system, a first double-acting plunger, a second double-acting plunger, power storage means adapted to be loaded in response.

to the travel of said first plunger, a fluid source, valve means operable in response to the movement of said first plunger and adapted selectively to be moved into a first position for establishing fluid connection between said fluid source and one sided said first and second plungers to thereby bring about movement of said plungers in a first direction, and adjustable control means for varying the speed of movement of said second plunger in said first direction,- said valve means also being movable into a second position for establishing fluid connection between said fluid source and thesecond side of said first plunger while simultaneously preventing fluid to the travel of said first plunger, a fluid source,

valve means operable in response to the movement of said first plunger and adapted selectively to be moved into a first position for establishing fluid connection between said fiuid source and one side of said first and second plungers to thereby bring about movement of said plungers in a first direction, adjustable control means for varying the speed of movement of said second plunger in said first tirection, said valve means also being movable into a second position for establishing fluid connection between said fluid source and the second side of said first plunger while simultaneously preventing fluid connection between said second plunger and said fluid source and establishing fluid connection between said power storage means and the second side of said second plunger to move said second plunger in a second direction, and means for by-passing said control means while fluid connection is established between said second side of said second plunger and said power storage means. i

8. In a control system, a first double-acting plunger, a second double-acting plunger, power storage means adapted to be loaded in response to the movement of said first plunger, valve means movable into a first position for establishing fluid connection between said fluid source and one side of said first and second plungers, means for maintaining a predetermined" pressure on said one side of said second plunger while said valve means is in said first position, irrespective of variations of pressure at the pressure side of said fluid source, and means responsive to a predetermined position of said first plunger for shifting said valve means into a second position to thereby interrupt fluid connection between said second plunger and said fluid source, while establishing fluid connection between said power storage means and the other side of said second plunger, and also establishing fluid con-, nection between the other side of said first" plunger and said fluid'source.

GEORGE A. WALDIE. 

